Video measurements of instantaneous forces of flapping wing vehicles

Flight Testing and Preliminary Analysis for Global System Identification of Ornithopter Dynamics Using On-board and Off-board Data

“…Additionally, a considerable difficulty is still obtaining realistic experimental data, particularly in free flight and in different flight regimes. Studies have found discrepancies between free-flight and wind tunnel data, 15,16,17 so that realistic insight for free flight ideally should be obtained in free-flight conditions.…”

Onboard/Offboard Sensor Fusion for High-Fidelity Flapping-Wing Robot Flight Data

“…eqs. [8][9][10][11][12][13][14][15][16][17][18][19] were found to converge in the static case, while during flight they vary to a limited extent, typically in conjunction with maneuvers. It can for instance be observed in fig.…”

“…Additionally, it is still considerably difficult to obtain realistic experimental data, particularly in free flight and in different flight regimes. Studies have found discrepancies between free-flight and wind tunnel data [16,17,18], suggesting that wind tunnel measurements approximate free-flight data only for specific clamping positions and in some flight conditions, so that realistic insight for free flight ideally should be obtained in free-flight conditions.…”

Free flight force estimation of a 23.5 g flapping wing MAV using an on-board IMU

“…Recently, the development of external motion tracking systems allowed to estimate the in-flight forces from recorded temporal evolutions of body position and orientation [5], [6], [7]. In general, an agreement has been reported between the in flight estimates and wind tunnel measurements, although differences were found in the direction of the wing stroke [8].…”